Sheet flasher for taking photographs



June 4, 1935- Y. YAMAGUCHI EI'AL SHEET FLASHER FOR TAKING PHOTOGRAPHS Filed April 25, 1933 2 SheetsShee1; 2

ATTORNEYS.

Patented a... 4, 1935 UNITED I STATES PATENT OFFICE k SHEET msnsa ron mama rno'roemrns Yohei Yamaguchi, Toshima Ku, Tokyo, and

Haruo Nakazawa, Kasugai-Gun,' Japan,

Kawanaka-Mura, Nishiassignors to Zaidan Hojin Bikagaku Kenkyujo, Tokyo, Japan Application In 4 Claims.

tween the two halves of which a leaf or powder of a combustible metal is stuffed or positioned, and in use, oxygen gas is to be produced within or filled into the envelope from outside. The object of the invention is to propose a flasher of sheet form which is smokeless and practically silent when flashed and also simple in construction and manufacture without necessitating to exhaust air therefrom, convenient for transportation and cheap, while having an excellent luminous efliciency.

In the drawings which show an embodiment of the new flasher according to the invention by way of merely example,

Fig. 1 shows a general view in elevation of the new flasher;

Fig. 2 is a partial sectional view of the new flasher showing details thereof in enlarged scale;

Fig. 3 is a side view of the flasher shown in Fig. 2;

Fig. 4 is a sectional view along the line A B in Fig. 2; 1

Fig. 5 is a side view of an electric lighter which may be conveniently used for lighting the new flasher; and

Fig. 6 is another side view of the lighter shown in Fig. 5, but viewed from a direction at right angle to that of Fig.5.

In the drawings, l and 2 are halves of an outer envelope, one of which is transparent or semitransparent yieldable member of paper or sheet form, such as cellophane paper, parchment paper, collodion film, celluloid film. 3 and 4 are halves of an inner envelope of the same-nature as the outer envelope. One of the halves of each envelope may be replaced by non-transparent member of sheet form. Also, only one envelope may be suificient for thepurpose, although the example shown in the drawings discloses the double envelopes. 5 is a light-reflective sheet positioned between the halves 2 and 4. 6 is a thin layer of combustible metal such as magnesium or aluminum, stuffed within the inner envelope, the layer being powder or leaves of the metal. I, I and l" are electric terminals also serving to close the ends 8 of the envelopes, the envelopes being closed to such an extent that the contents therein are not discharged, but not necessarily gas tight. 9 is a flat metallic cover in which a container H) for oxygen producing i mixture H such as of metallic powder, potassium are pushed into the corresponding terminals 22,

April 25, 1933, Serial'No. 667,892

Japan March 1'7, 1932 chlorate, and glue pasted together. I2 is a resistance wire imbedded into the mixture; l3 and Il are conducting wires from I to l2 and I2 to 1' respectively. [5 is a flat passage one end of which is communicated to the end of the cover 9 and the other end of which is communicated to a strainer I6 made of, say, a cloth bag. H is an ignitingmaterial such as a mixture of sulphur and potassium chlorate suitably enveloped.

I8 is a resistance wire to ignite the mixture. l9 and 20 are conducting wires between I and i1, and I1 and 1" respectively. 2| is a lighter containing electric cells and provided with terminals 22, 23 andjfl and also with buttons 25 and 26. When, say, a. button 25 is pressed, a circuit including 22 and 23 is closed, while when the button 26'is pressed, another circuit containing 23 and 24 is closed.

In use, the terminals 1, I and 1" of the flasher 23 and 24 of the lighter sothat the lighter becomes a safe handle for holding the flasher. Whena button 25 is pressed, the charge in the container I0 is heated by the resistance wire l2, which flrstly heat the metallic powder of the oxygen source II. The heated metallic powder affects to heat the oxygen producing sub stance ofthe source I I so that oxygen gas is thus produced immediately. This gas passes through the passage 15 and 'flows out to the space within the inner envelope after strained by the strainer 16, and is filled up in the space. around the metallic layer 6. This oxygen gas does not escape from the envelope owing to the absence of pressure difference between the inside and outside oi the envelope. Then the button 25 is released and 26 is pressed, by which operationthe igniting material is started to ignite the combustible metallic layer surrounded by the oxygen gas.

The weight of the combustible metal used in the flasher is very small, say, a few decigrams in usual cases, and that of the oxygen gas necessary for the combustion thereof is also so. Therefore, when it is flashed when taking photograph, the expansion of the sheet flasher of the invention is small and the film or sheet of the flasher keeps the envelope as before without destroying by the explosion. Moreover, the speed of combustion of the metal is very large. In other words, its combustion is finished within an enormously'short time, so that the film or sheet employed is not .practically burnt off. This is indeed so even when it is made of celluloid. Therefore the smoke produced by the flashing can be kept within the envelope and is not blown out.

there occurs practically no explosion when the flasher'of the inventionis flashed.

It is a known fact that the source of luminosity due to the combustion of magnesium or aluminum when taking photograph, lies in chiefly radiation of solid body at high temperature. Therefore it is a matter of course that as the temperature of the hot body is higher, so that the efliciency of the luminosity is better. When a combustible metal is combustioned in atmospheric air with or without the supply of an oxidizing agent, the heat of combustion of the metal is used to heat the useless substances other than the metal oxide so that the temperature is necessarily decreased more or less.

As the energy of radiation is proportional to about four power of absolute temperature, the efiiciency of luminosity may be promoted by so many times or so many ten times when the combustion is carried out in the atmosphere of pure oxygen. However, when a metal is combustioned in oxygen atmosphere within a flasher, it re- 1 quires a container which will keep oxygen gas in constant pressure, and also which is of constant form and perfectly gas tight for the purpose of transportation and conservation. All of the known flashers belong to the above explained class.

As before explained the new flasher according to the invention does not require a container of constant form or of gas tight construction, and also accompanies no necessity of exhausting atmospheric air in the manufacture. It is simple in construction and also in use, convenient and safe for transportation or carrying while the cost is cheap. It is almost smokeless and silent and of prominent efliciency when flashed due to its being sheet form.

The foregoing example may of course be modified without departing from the scope of the invention. For instances, the one half of the transparent or semitransparent film or sheet may be replaced by an opaque film or sheet or by light reflective sheet. Or the light reflective sheet may also be entirely omitted. Further, the film or sheet may be partially transparent or semitransparent instead of wholly so. When the oxygen gas necessary for the combustion is to be supplied in use, a separate oxygen supplier or producer may be furnished which may be communicated by a convenient means to the new sheet flasher. In the latter case it is of no use to provide the oxygen producing substance H and its accessory parts which are shown in the figures. Also the invention is never restrictedto any detailed constructions as shown.

What we claim is:-

1. A sheet flasher for taking photographs, comprising a closed envelope, one of the two sides of which is a transparent yieldable member, the other side being a non-transparent sheet, means for producing oxygen gas contained in the envelope, a combustible metal member in the envelope and means for igniting the metal member in the presence of the oxygen gas produced in the envelope.

2. A sheet flasher for taking photographs, comprising a closed envelope, one of'two sides of which is a semitransp'arent yieldable member, the other side being a non-transparent sheet, means for producing oxygen gas, a combustible metal member in the envelope and means for igniting the metal member in the presence of the oxygen gas produced in the envelope.

3. A sheet flasher for taking photographs, comprising a closed envelope, at least one of the two sides of which is formed by a transparent yieldable member, means for producing oxygen gas contained in the envelope, a combustible metal member in the envelope and means for igniting the metal member in the presence of the oxygen gas in the envelope.

4. A sheet flasher for taking photographs, comprising a closed envelope, at least one of the two sidesof which is formed by a semi-transparent yieldable member, means for producing oxygen gas contained in the envelope, a combustible metal member in the envelope and means for igniting the metal member in the presence of the oxygen gas in the envelope.

YOHEI YAMAGUCHI. I HARUO NAKAZAWA. 

